Fig. 5.
Hypothetical scheme depicting how INDO inhibits plasmacytomagenesis. Pristane stimulates macrophages and plastic discs stimulate fibroblasts to produce PGE2 that acts in an autocrine fashion to cause these cells how to produce IL-6, IGF-1, and IGFBP5 that stimulate developing PCT cells to survive and proliferate. PGE2 inhibits production of macrophage factors IL-12, IL-1, IL-2, and MHCII (see text) that stimulate cytotoxic T lymphocyte formation. This potentially generates an immunologically permissive environment for antigenic plasma cells to escape immunological surveillance. Proof that this is a factor in plasmacytomagenesis is not yet available.
